In various memories, data signals may be provided between devices over lines (e.g. bit lines). In some cases, providing data signals in this manner includes precharging the lines to a certain logic level (e.g. logic high) and subsequently driving the lines with logic levels representative of data (e.g. input/write data, output/read data, address data, command data, etc.) to be provided to the lines. A logic high may be a voltage associated with a high supply voltage, such as VCC, and a logic low may be a voltage associated with a low supply voltage, such as ground.
Typically, one or more of the lines are precharged to a logic high. Some systems for example, may precharge all lines, whereas others may precharge one line in each of a plurality of complementary pairs of lines. Precharge operations consume power by driving the lines to a precharge voltage. Following a precharge operation, lines may be driven to respective logic levels representative of data by selectively maintaining the precharged logic level, or by changing the logic level. Consequently, charge (and as a result power) may be consumed. For example, if a line is precharged to a logic high, the charge required to precharge the line to a logic high will be wasted when the line is driven to a logic low. The charge on the line will be discharged by, for example, coupling the line to a low supply voltage to drive the line to the appropriate logic state.
Generally, the length of the line may determine the total capacitance of a line and, therefore, the charge needed to drive a line to a logic high. It follows that the longer a line, the more charge that may be consumed as a result of discharging charge in a conventional precharge operation.
Many devices today include memories having long lines and are operated at relatively fast, and steadily increasing, operating speeds. As a result, performance of these devices has improved. However, improvements in power consumption is desirable given that many of these memories are used in battery power devices, such as mobile devices.